This invention relates to a three-position, four-way rotary valve of the type in which a valve member is rotatably mounted in a valve housing. When the valve member is rotated in one direction from a neutral position to a first active position, passages in the valve enable pressurized fluid to flow to the first side of a utilization device (e.g., a hydraulic cylinder) while additional passages enable pressure fluid to dump to drain from the other side of the utilization device. If the valve member is rotated in the opposite direction from its neutral position to a second active position, the second side of the utilization device is pressurized and, at the same time, the first side of the utilization device is connected to drain.
Such a valve may, for example, be used in connection with a hand-manipulated tool whose operating elements are actuated by a hydraulic cylinder which is controlled by the valve.
More specifically, the invention relates to a valve in which the valve member is rotated between its positions by manually turning an actuator which is associated with the valve. Even more specifically, the invention relates to a three-position, four-way rotary valve whose valve member may be rotated between its various positions by turning the valve actuator through only a relatively small angle so as to facilitate simple and easy actuation of the valve. A three-position, four-way, "short-stroke" rotary valve of this general type is disclosed in Lapp U.S. Pat. No. 4,342,332. In that valve, the various ports and passages in the valve member and the valve housing are arranged and located so as to enable the valve member to move between its various positions while turning through a comparatively small angle such as 30 degrees rather than through the more conventional angle of 45 degrees.